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"Nigel Perry"
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Participation, citizenship and intergenerational relations in children and young people's lives : children and adults in conversation
\"In 2012, over 200 academics who are active in international childhood and youth research gathered together alongside young people for a unique ICYRNet conference where they debated and discussed participatory approaches. [This book] continues the dialogue between young people and adults that started then. This edited collection draws together work from six countries about participatory research and intergenerational relations. Adopting participatory techniques, the editors worked with children and young people to co-author three chapters that each reflect young people's interpretations of three chapters written by adults. This provides a unique insight into how children and young people view research which is about them as well as highlighting their perspectives on research which resonates with their own life experiences.\"--Provided by publisher.
Book
New Zealand glowworm (Arachnocampa luminosa) bioluminescence is produced by a firefly-like luciferase but an entirely new luciferin
The New Zealand glowworm,
Arachnocampa luminosa
, is well-known for displays of blue-green bioluminescence, but details of its bioluminescent chemistry have been elusive. The glowworm is evolutionarily distant from other bioluminescent creatures studied in detail, including the firefly. We have isolated and characterised the molecular components of the glowworm luciferase-luciferin system using chromatography, mass spectrometry and
1
H NMR spectroscopy. The purified luciferase enzyme is in the same protein family as firefly luciferase (31% sequence identity). However, the luciferin substrate of this enzyme is produced from xanthurenic acid and tyrosine, and is entirely different to that of the firefly and known luciferins of other glowing creatures. A candidate luciferin structure is proposed, which needs to be confirmed by chemical synthesis and bioluminescence assays. These findings show that luciferases can evolve independently from the same family of enzymes to produce light using structurally different luciferins.
Journal Article
Leaf colour polymorphisms: a balance between plant defence and photosynthesis
Whether plants use leaf colour to deter herbivores remains controversial. The warning signal hypothesis predicts that red pigmentation is adaptive by reducing herbivory; plants with predominantly red foliage should have higher fitness than those with green leaves. Despite many discussions, this prediction has rarely been tested, and alternative, non‐exclusive hypotheses cannot be ruled out. We have exploited leaf colour polymorphism in Pseudowintera colorata to test the warning signal hypothesis and to address possible alternative explanations. Consistent with warning signals, redder foliage contained higher concentrations of polygodial, a sesquiterpene dialdehyde with strong antifeedant properties, and incurred less herbivory than green leaves. Redder plants hosted 22% fewer lepidopteran leafroller larvae than neighbouring green plants. However, contrary to the predictions of the hypothesis, there were no differences in fitness parameters between red and green plants. Overall leaf canopy colour was not a significant predictor of the number of seeds per fruit or of mean seed weight. This may be explained by differences in photosynthesis: green P. colorata leaves had 47% higher maximum CO₂ assimilation rates than matched red leaves from neighbouring plants. These results indicate that the benefits of deterring insect herbivores by signalling may be balanced by the higher photosynthetic rate of non‐signalling plants. A balance between signalling and photosynthesis is a novel mechanism for the maintenance of leaf colour polymorphisms in nature. Synthesis. Anthocyanin pigments may simultaneously serve multiple functions within leaves, and individuals of the same plant species may use different strategies to cope with insect herbivores. Therefore, investigations into the role of these pigments in plant–insect interactions need to consider plant physiology and the diversity of plant defence mechanisms.
Journal Article
Red leaf margins indicate increased polygodial content and function as visual signals to reduce herbivory in Pseudowintera colorata
• Red‐pigmented leaf margins are common, but their functional significance is unknown. We hypothesized that red leaf margins reduce leaf herbivory by signalling to herbivorous insects the presence of increased chemical defences. • Leaves were collected from a natural population of Pseudowintera colorata. Margin size, herbivory damage, anthocyanin content and concentrations of polygodial, a sesquiterpene dialdehyde with antifeedant properties, were quantified. Feeding trials involving larvae of Ctenopseustis obliquana, a generalist herbivore, were conducted on red‐ and green‐margined P. colorata leaves in darkness, or under white, green or red light. • Leaves with wider red margins contained higher concentrations of polygodial and anthocyanins, and incurred less natural herbivory. In trials under white light, C. obliquana consumed disproportionately more green‐ than red‐margined leaf laminae. Larvae exhibited no feeding preference when light was manipulated such that leaf colour discrimination was impaired. • Red leaf margins provide a reliable and effective visual signal of chemical defence in P. colorata. Ctenopseustis obliquana larvae perceive and respond to the colour of the leaf margins, rather than to olfactory signals. Our study provides direct experimental evidence for aposematic coloration in red leaves.
Journal Article
The Effect of Turmeric (Curcuma longa) Extract on the Functionality of the Solute Carrier Protein 22 A4 (SLC22A4) and Interleukin-10 (IL-10) Variants Associated with Inflammatory Bowel Disease
Inflammatory bowel disease (IBD) is a chronic relapsing disease. Genetic predisposition to the disease reduces an individual’s capacity to respond appropriately to environmental challenges in the intestine leading to inappropriate inflammation. IBD patients often modify their diet to mitigate or reduce the severity of inflammation. Turmeric (Curcuma longa L., Zingiberaceae) has historically been used in Chinese, Hindu, and Ayurvedic medicine over several centuries to treat inflammatory disorders. To understand how turmeric may influence the consequences of a genetic predisposition to inappropriate inflammation, we used HEK293 cells to examine the in vitro capacity of turmeric extract and fractions to affect the functionality of two gene variants, solute carrier protein 22 A4 (SLC22A4, rs1050152) and interleukin-10 (IL-10, rs1800896) associated with IBD. We found that a turmeric extract and several chromatographically separated fractions beneficially affected the variants of SLC22A4 and IL-10 associated with IBD, by reducing inappropriate epithelial cell transport (SLC22A4, 503F) and increasing anti-inflammatory cytokine gene promoter activity (IL-10, −1082A). The effect of turmeric on the IL-10 variant was strongly associated with the curcumin content of the extract and its fractions.
Journal Article
Herbicidal β‐triketones are compartmentalized in leaves of Leptospermum species: localization by Raman microscopy and rapid screening
The New Zealand mānuka shrub, Leptospermum scoparium, and the Australian L. morrisonii produce herbicidal β‐triketones in their leaves. The localization of these potential self‐toxicants has not been proven. We investigated the localization of these compounds in leaves using Raman microscopy. The results are presented as heat maps derived from principal component analysis (PCA) of the Raman spectra from sampling grids of leaf sections. This approach used undirected, data‐driven analysis to qualitatively distinguish localized plant chemistry. The presence of β‐triketones and lipophilic flavonoids was confirmed by GC‐MS and¹H NMR spectroscopy. Grandiflorone was compartmentalized within the leaf oil glands of L. morrisonii. Leptospermum scoparium also contained high concentrations of grandiflorone, previously reported as only a trace component in essential oils, localized in the oil glands in the leaves of varieties from diverse geographical locations. Raman microscopy was used to probe the chemistry of oil glands in several ornamental mānuka varieties, revealing high concentrations of bioactive flavonoids localized in these glands. The compartmentalization of β‐triketones within oil glands inside leaves of Leptospermum shrubs may defend the plants against herbicidal activity.
Journal Article
A dahlia flower extract has antidiabetic properties by improving insulin function in the brain
Abstract
Butein, a rare chalcone found in the toxic plant Toxicodendron vernicifluum, has been shown to regulate glucose homeostasis via inhibition of the nuclear factor kappa-B kinase subunit beta (IKKβ)/nuclear factor kappa B (NF-κB) pathway in the brain. Here, we investigated whether the nonpoisonous plant Dahlia pinnata could be a source of butein as a potential treatment for type 2 diabetes (T2D). In mice fed a high-fat diet (HFD) to induce glucose intolerance, an oral D. pinnata petal extract improved glucose tolerance at doses of 3.3 mg/kg body weight and 10 mg/kg body weight. Surprisingly, this effect was not mediated by butein alone but by butein combined with the closely related flavonoids, sulfuretin and/or isoliquiritigenin. Mechanistically, the extract improved systemic insulin tolerance. Inhibition of phosphatidylinositol 3-kinase to block insulin signaling in the brain abrogated the glucoregulatory effect of the orally administered extract. The extract reinstated central insulin signaling and normalized astrogliosis in the hypothalamus of HFD-fed mice. Using NF-κB reporter zebrafish to determine IKKβ/NF-κB activity, a potent anti-inflammatory action of the extract was found. A randomized controlled crossover clinical trial on participants with prediabetes or T2D confirmed the safety and efficacy of the extract in humans. In conclusion, we identified an extract from the flower petals of D. pinnata as a novel treatment option for T2D, potentially targeting the central regulation of glucose homeostasis as a root cause of the disease.
Journal Article
Regiospecific Analyses of Triacylglycerols of Hoki (Macruronus novaezelandiae) and Greenshell™ Mussel (Perna canaliculus)
The lipid profiles of the two most important New Zealand marine oil sources were investigated, with particular attention to the regioisomeric compositions of triacylglycerides (TAG), using ¹³C-nuclear magnetic resonance analysis. Oils from hoki (Macruronus novaezelandiae) and Greenshell™ mussel (Perna canaliculus) (GSM) were analyzed for their lipid content, lipid class and fatty acid profile. The regiospecific distribution of long chain (C ≥ 20) polyunsaturated fatty acids (LC-PUFA) between the sn-1,3 and sn-2 glycerol positions was calculated from ¹³C responses in the carbonyl region in the triacylglycerol fraction. Rendered hoki oil (RHO) produced from the viscera and filleting discards, had a similar lipid profile to that of hoki liver oil (HLO) confirming that the liver is the major source of oil in RHO. The regioisomeric distribution of fatty acids showed differences between the two oil sources. Docosahexaenoic acid (DHA) had a regioisomeric distributional preference to the sn-2 position in TAG from all the oils (59.2% HLO, 54.3% RHO and 63.4% GSM). Eicosapentaenoic acid (EPA) had a more even distribution along the triacylglycerol backbone in hoki TAG (29.1% HLO, 33.6% RHO) while there was a slight sn-2 positional preference in the GSM TAG (37.6%). This regioisomeric information is vital to distinguish LC-PUFA-rich marine oils from other marine sources for authentication purposes.
Journal Article